Memory device and operating method thereof

ABSTRACT

A memory device includes an erase operation controller for performing an erase operation on a memory block; an erase suspend count manager for managing an erase suspend count representing a number of times the erase operation is suspended until the erase operation on the memory block is completed; and a program parameter value determiner for determining a parameter value to be used for a program operation on the memory block, based on the erase suspend count.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. § 119(a) toKorean patent application number 10-2018-0127053, filed on Oct. 23,2018, the entire disclosure of which is incorporated herein by referencein its entirety.

BACKGROUND Field of Invention

The present disclosure generally relates to a memory device and anoperating method thereof, and more particularly, to a memory devicecapable of performing a program operation, using different parametervalues depending on an erase depth of a memory block, and an operatingmethod of the memory device.

Description of Related Art

A memory system may include a memory controller and a memory device.

The memory device may store data and output stored data under thecontrol of the memory controller. Also, the memory device may beconfigured as a volatile memory device in which stored data disappearswhen the supply of power is interrupted, or be configured as anonvolatile memory device in which stored data is retained even when thesupply of power is interrupted.

SUMMARY

Embodiments provide a memory device capable of performing a programoperation, using different parameter values depending on an erase depthof a memory block, and an operating method of the memory device.

In accordance with an aspect of the present disclosure, there isprovided a memory device including an erase operation controllerconfigured to perform an erase operation on a memory block; an erasesuspend count manager configured to manage an erase suspend countrepresenting a number of times the erase operation is suspended untilthe erase operation on the memory block is completed; and a programparameter value determiner configured to determine a parameter value tobe used for a program operation on the memory block, based on the erasesuspend count.

In accordance with another aspect of the present disclosure, there isprovided a method for operating a memory device, the method includingperforming an erase operation on a memory block when an erase commandcorresponding to the memory block is received; suspending the eraseoperation on the memory block when an erase suspend commandcorresponding to the memory block is received while the erase operationon the memory block is being performed; restarting the erase operationon the memory block when an erase restart command on the memory block isreceived while the erase operation on the memory block is suspended;counting a number of times the erase command is received until the eraseoperation on the memory block is completed to generate a counted number;and determining a parameter value to be used for a program operation onthe memory block, based on the counted number.

In accordance with another aspect of the present disclosure, there isprovided a memory device including a memory block configured to storedata; a peripheral circuit configured to perform erase and programoperations on the memory block; an erase operation controller configuredto control the peripheral circuit to perform the erase operation; and aprogram operation controller configured to control the peripheralcircuit to perform the program operation with a parameter valuedepending on a number of times the erase operation is suspended untilcompletion thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments will now be described more fully with reference tothe accompanying drawings; however, elements and features of the presentinvention may be configured or arranged differently than disclosedherein. Thus, the present invention is not limited to the embodimentsset forth herein. Rather, these embodiments are provided so that thisdisclosure is thorough and complete and fully conveys the scope of theembodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. Like reference numerals refer to like elements throughout.Also, throughout the specification, reference to “an embodiment,”“another embodiment” or the like is not necessary to only oneembodiment, and different references to any such phrase are notnecessarily to the same embodiment(s).

FIG. 1 is a diagram illustrating a memory system in accordance with anembodiment of the present disclosure.

FIG. 2 is a diagram illustrating an exemplary memory controller shown inFIG. 1.

FIG. 3 is a diagram illustrating a memory device in accordance with anembodiment of the present disclosure.

FIG. 4 is a diagram illustrating exemplary control logic shown in FIG.3.

FIG. 5 is a diagram illustrating an example of managing an erase suspendcount for each memory block.

FIG. 6 is a diagram illustrating an exemplary threshold voltagedistribution of memory cells on which a normal program operation isperformed.

FIG. 7 is a diagram illustrating an exemplary erase pulse applied in anerase operation.

FIG. 8 is a diagram illustrating an exemplary threshold voltagedistribution of memory cells on which an erase operation is performed.

FIG. 9 is a diagram illustrating an exemplary threshold voltagedistribution of memory cells on which a soft program operation isperformed.

FIG. 10 is a diagram illustrating an exemplary process of suspending andrestarting an erase operation.

FIG. 11 is a diagram illustrating an exemplary threshold voltagedistribution of memory cells depending on an erase suspend count.

FIG. 12 is a diagram illustrating a program parameter policy inaccordance with an embodiment of the present disclosure.

FIGS. 13 to 16 are diagrams illustrating an exemplary program parameterselected in a program operation using an ISPP scheme.

FIG. 17 is a flowchart illustrating an operating method of the memorydevice in accordance with an embodiment of the present disclosure.

FIG. 18 is a flowchart illustrating an operating method of the memorydevice in accordance with an embodiment of the present disclosure.

FIG. 19 is a diagram illustrating an exemplary memory block.

FIG. 20 is a diagram illustrating an embodiment of a three-dimensionallyconfigured memory block.

FIG. 21 is a diagram illustrating another embodiment of athree-dimensionally configured memory block.

FIGS. 22 to 25 are diagrams illustrating other examples of the memorysystem including the memory device shown in FIGS. 1 to 3.

DETAILED DESCRIPTION

In the present disclosure, advantages, features and methods forachieving them will become more apparent after a reading of thefollowing embodiments taken in conjunction with the drawings. Thepresent invention may, however, be embodied in different forms and thusshould not be construed as being limited to the embodiments set forthherein. Rather, these embodiments are provided to describe the presentinvention in detail to the extent that those skilled in the art to whichthe disclosure pertains may easily practice the present invention.

In the entire specification, when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the another element or be indirectly connectedor coupled to the another element with one or more intervening elementsinterposed therebetween. Also, when an element is referred to as being“between” two elements, it can be the only element between the twoelements, or one or more intervening elements may also be present. Inaddition, when an element is referred to as “including” a component,this indicates that the element may further include another componentinstead of excluding another component unless there is differentdisclosure.

Various embodiments of the present disclosure are described below withreference to the accompanying drawings.

FIG. 1 is a diagram illustrating a memory system in accordance with anembodiment of the present disclosure.

Referring to FIG. 1, the memory system 2000 may include a memory device2200 configured to store data and a memory controller 2100 configured tocontrol the memory device 2200 according to requests of a host 1000.

The host 1000 may communicate with the memory system 2000, using atleast one interface protocol among a Non-Volatile Memory express (NVMe),a Peripheral Component Interconnect-Express (PCI-E), an AdvancedTechnology Attachment (ATA), a Serial ATA (SATA), a Parallel ATA (PATA),a Universal Serial Bus (USB), a Multi-Media Card (MMC), an EnhancedSmall Disk Interface (ESDI), an Integrated Drive Electronics (IDE), aMobile Industry Processor Interface (MIPI), a Universal Flash Storage(UFS), a Small Computer Small Interface (SCSI), and a Serial AttachedSCSI (SAS). More generally, the host 1000 may communicate with thememory system 2000 using any suitable protocol or technique.

The memory controller 2100 may control overall operations of the memorysystem 2000, and control data exchange between the host 1000 and thememory device 2200. In a program operation, the memory controller 2100may transmit a command, an address, data, etc. to the memory device2200. In a read operation or erase operation, the memory controller 2100may transmit a command, an address, and the like to the memory device2200.

The memory device 2200 may be configured as a volatile memory device inwhich stored data disappears when the supply of power is interrupted ora nonvolatile memory device in which stored data is retained even whenthe supply of power is interrupted. The memory device 2200 may perform aprogram operation, a read operation, an erase operation, and the likeunder the control of the memory controller 2100. The memory device 2200may include a plurality of memory blocks configured to store data.

FIG. 2 is a diagram illustrating an example of the memory controllershown in FIG. 1.

Referring to FIG. 2, the memory controller 2100 may include a hostinterface 2110, a central processing unit (CPU) 2120, a memory interface2130, a buffer memory 2140, an error correction circuit 2150, and aninternal memory 2160. The host interface 2110, the memory interface2130, the buffer memory 2140, the error correction circuit 2150, and theinternal memory 2160 may be controlled by the CPU 2120.

The host interface 2110 may exchange data with the host 1000, usingvarious interface protocols. For example, the host interface 2110 maycommunicate with the host 1000, using at least one interface protocolamong a Non-Volatile Memory express (NVMe), a Peripheral ComponentInterconnect-Express (PCI-E), an Advanced Technology Attachment (ATA), aSerial ATA (SATA), a Parallel ATA (PATA), a Universal Serial Bus (USB),a Multi-Media Card (MMC), an Enhanced Small Disk Interface (ESDI), anIntegrated Drive Electronics (IDE), a Mobile Industry ProcessorInterface (MIPI), a Universal Flash Storage (UFS), a Small ComputerSmall Interface (SCSI), and a Serial Attached SCSI (SAS). Moregenerally, the host interface 2110 may communicate with the host 1000using any suitable protocol or technique.

The host interface 2110 may receive a program request and user datacorresponding to the program request from the host 1000. The hostinterface 2100 may transfer the program request to the CPU 2120, andtransfer the user data to the buffer memory 2140. The host interface2110 may receive a read request or erase request from the host 1000, andtransfer the received read request or erase request to the CPU 2120.

The CPU 2120 may perform various calculations or generate a command andan address so as to control the memory device 2200. For example, the CPU2120 may generate various commands necessary for a program operation, aread operation, and an erase operation.

The CPU 2120 may translate a logical address received from the host 1000into a physical address so as to control an operation of the memorydevice 2200. The CPU 2120 may translate a logical address into aphysical address or translate a physical address into a logical address,using an address mapping table stored in the internal memory 2160. TheCPU 2120 may update the address mapping table when new data isprogrammed to the memory device 2200 or when data stored in the memorydevice 2200 is erased.

In an embodiment, the CPU 2120 may control the memory device 2200 toperform an erase operation. For example, when an erase request isreceived from the host 1000, the CPU 2120 may generate an erase commandand an address, and transmit the generated erase command and thegenerated address to the memory device 2200.

In an embodiment, when the memory device 2200 is requested to performanother operation while performing an erase operation, the CPU 2120 maycontrol the memory device 2200 to suspend the erase operation beingcurrently performed. For example, the CPU 2120 may generate an erasesuspend command and an address, and transmit the generated erase suspendcommand and the generated address to the memory device 2200. In anembodiment, the other operation, which is requested while the eraseoperation is performed, may be a program operation or read operation,but embodiments of the present disclosure are not limited thereto. Forexample, the CPU 2120 may control an operation of the memory device 2200within a range satisfying a requested Quality of Service (QoS). Forexample, in order to satisfy a QoS for a read operation while the memorydevice 2200 is performing an erase operation, the CPU 2120 may suspendthe erase operation being performed by the memory device 2200, andcontrol the memory device 2200 to perform the read operation. Forexample, when a request for requesting the CPU 2120 to flush data storedin the buffer memory 2140 to the memory device 2200 is received from thehost 1000 while the memory device 2200 is performing an erase operationor when it is autonomously determined that it is necessary to flush datastored in the buffer memory 2140 to the memory device 2200, the CPU 2120may suspend the erase operation being performed by the memory device2200, and control the memory device 2200 to perform a program operation.

In an embodiment, when the memory device 2200 completes performance ofthe other operation, the CPU 2120 may control the memory device 2200 torestart the suspended erase operation. For example, the CPU 2120 maygenerate an erase restart command and an address, and transmit thegenerated erase restart command and the generated address to the memorydevice 2200.

In an embodiment, the CPU 2120 may control the memory device 2200 toperform a program operation. The program operation may include at leastone of a soft program operation and a normal program operation. The softprogram operation may be an operation for increasing a threshold voltageof memory cells included in a memory block or narrowing the width of athreshold voltage distribution. The normal program operation may be anoperation for storing data in memory cells included in a memory block.The CPU 2120 may generate a program command and an address for the softprogram operation or the normal program operation, and transmit thegenerated program command and the generated address to the memory device2200.

In an embodiment, when the memory device 2200 completes an eraseoperation on a memory block, the CPU 2120 may generate a program commandand an address, and transmit the generated program command and thegenerated address to the memory device 2200 such that a soft programoperation on the corresponding memory block can be performed.

In an embodiment, the CPU 2120 may generate a status check command tocheck whether the memory device 2200 is performing an erase operation oranother operation or has completed the erase operation or the otheroperation, and transmit the generated status check command to the memorydevice 2200. The CPU 2120 may check whether the memory device 2200 isperforming the erase operation or the other operation or has completedeither of those operations based on a status check result received fromthe memory device 2200 corresponding to the status check command.

The memory interface 2130 may communicate with the memory device 2200using various interface protocols, such as any of those identifiedabove.

The buffer memory 2140 may temporarily store data while the memorycontroller 2100 controls the memory device 2200. For example, the buffermemory 2140 may temporarily store user data received from the host 1000until a program operation is completed.

The error correction circuit 2150 may perform error correction encodingduring a program operation. The error correction circuit 2150 mayperform error correction decoding during a read operation.

The internal memory 2160 may be used as a storage for storing variousinformation for an operation of the memory controller 2100. The internalmemory 2160 may store a plurality of tables. For example, the internalmemory 2160 may store an address mapping table in which logicaladdresses and physical addresses are mapped.

FIG. 3 is a diagram illustrating a memory device in accordance with anembodiment of the present disclosure. The memory device shown in FIG. 3may be applied to the memory system shown in FIGS. 1 and 2.

The memory device 2200 may include control logic 2210, a peripheralcircuit 2220, and a memory cell array 2240.

The control logic 2210 may control the peripheral circuit 2220 includingcomponents thereof under the control of the memory controller 2100 shownin FIGS. 1 and 2.

The control logic 2210 may control the peripheral circuit 2220 inresponse to a command CMD and an address ADD, which are received fromthe memory controller 2100 through an input/output circuit 2226. Forexample, the control logic 2210 may output an operation signal OP_CMD, arow address RADD, a column address CADD, page buffer control signalsPBSIGNALS, and an allow bit VRY_BIT<#> in response to the command CMDand the address ADD. The control logic 2210 may determine whether averify operation has passed or failed in response to a pass or failsignal PASS or FAIL received from a current sensing circuit 2234.

The control logic 2210 may perform an erase operation, a programoperation or the like on a selected memory block by controlling theperipheral circuits 2220. When the control logic 2210 is requested tosuspend an erase operation on a memory block while performing the eraseoperation, the control logic 2210 may suspend the erase operation bycontrolling the peripheral circuits 2220. When the control logic 2210 isrequested to restart the erase operation on the memory block in a statein which the erase operation is suspended, the control logic 2210 mayrestart the erase operation by controlling the peripheral circuit 2220.

The control logic 2210 may control the peripheral circuit 2220 toperform a program operation on a memory bock of which erase operationhas been completed. For example, the control logic 2210 may determineparameter values used to perform the program operation on the memoryblock, and control the peripheral circuit 2220 to perform the programoperation on the memory block using the determined parameter values. Forexample, parameter values used to perform the program operation mayinclude at least one of a program start voltage, a number of programloops, and a program step voltage.

The peripheral circuit 2220 may perform a soft program operation forincreasing a threshold voltage of memory cells, a normal programoperation for storing data in memory cells, a read operation foroutputting data stored in memory cells, an erase operation for erasingdata stored in memory cells, and the like.

The peripheral circuit 2220 may include a voltage generation circuit2222, a row decoder 2224, the input/output circuit 2226, a columndecoder 2228, a page buffer group 2232, and the current sensing circuit2234.

The voltage generation circuit 2222 may generate various operatingvoltages Vop used in program, read, and erase operations in response tothe operation signal OP_CMD received from the control logic 2210. Forexample, the voltage generation circuit 2222 may transfer a programvoltage, a verify voltage, a pass voltage, a read voltage, an erasevoltage, a turn-on voltage, and the like to the row decoder 2224.

The row decoder 2224 may transfer the operating voltages Vop to locallines LL connected to a selected memory block among memory blocks of thememory cell array 2240 in response to the row address RADD received fromthe control logic 2210. The local lines LL may include local word lines,local drain select lines, and local source select lines. In addition,the local lines LL may include various lines such as a source line,which are connected to the memory block.

The input/output circuit 2226 may transfer the command CMD and theaddress ADD, which are received from the memory controller 2100 throughinput/output lines IO, to the control logic 2210, or exchange data DATAwith the column decoder 2228.

The column decoder 2228 may transfer data between the input/outputcircuit 2226 and the page buffer group 2232 in response to a columnaddress CADD received from the control logic 2210. For example, thecolumn decoder 2228 may exchange data with page buffers PB1 to PBmthrough data lines DL, or exchange data with the input/output circuit2226 through column lines CL.

The page buffer group 2232 may be connected to bit lines BL1 to BLmcommonly connected to memory blocks BLK1 to BLKi. The page buffer group2232 may include a plurality of page buffers PB1 to PBm connected to thebit lines BL1 to BLm. For example, one page buffer may be connected tocorresponding one of the bit lines. The page buffers PB1 to PBm mayoperate in response to the page buffer control signals PBSIGNALSreceived from the control logic 2210. For example, in a programoperation, the page buffers PB1 to PBm may temporarily store programdata received from the memory controller 2100, and adjust a voltageapplied to the bit lines BL1 to BLm according to the program data. Also,in a read operation, the page buffers PB1 to PBm may temporarily storedata received through the bit lines BL1 to BLm, or sense a voltage orcurrent of the bit lines BL1 to BLm.

During a read or verify operation, the current sensing circuit 2234 maygenerate a reference current in response to the allow bit VRY_BIT<#>received from the control logic 2210, and output a pass signal PASS or afail signal FAIL by comparing a sensing voltage VPB received from thepage buffer group 2232 with a reference voltage generated by thereference current.

The memory cell array 2240 may include a plurality of memory blocks BLK1to BLKi in which data is stored. User data and various information usedto perform an operation of the memory device 2200 may be stored in thememory blocks BLK1 to BLKi. The memory blocks BLK1 to BLKi may beimplemented in a two-dimensional structure or a three-dimensionalstructure, and be configured identical to one another.

Any of the memory blocks BLK1 to BLKi may be a Single Level Cell (SLC)block or a Multi Level Cell (MLC) block according to the number of bitsof data stored in a memory cell of that memory block. The SLC block maybe a block driven in a manner that stores data of 1 bit in one memorycell, and the MLC block may be a block driven in a manner that storedata of 2 bits or more in one memory cell. That is, the memory device2200 may include at least one of an n-bit MLC block and an SLC block.n-bit data may be programmed in each of memory cells included in then-bit MLC block, and data of 1 bit may be programmed in each of memorycells included in the SLC block. Here, ‘n’ may be a natural number of 2or more.

FIG. 4 is a diagram illustrating control logic, such as that shown inFIG. 3.

Referring to FIG. 4, the control logic 2210 in accordance with anembodiment of the present disclosure may include an erase operationcontroller 2212 a, an erase suspend count manager 2212 b, a programparameter value determiner 2212 c, a policy storage 2212 d, and aprogram operation controller 2212 e.

The erase operation controller 2212 a may control an erase operation ona memory block.

In an embodiment, when an erase command and an address are received fromthe memory controller, the erase operation controller 2212 a may performan erase operation on a memory block corresponding to the receivedaddress. For example, the erase operation controller 2212 a maydetermine a level of an erase voltage to be applied to the memory block,a time of which the erase voltage is applied, a number of which theerase voltage is applied, and the like, and perform the erase operationon the memory block by using these determined parameters. In anembodiment, default values may be used as the level of the erase voltageto be applied to the memory block, the time of which the erase voltageis applied, the number of which the erase voltage is applied, and thelike.

In an embodiment, the erase operation controller 2212 a may suspend anerase operation on a memory block when an erase suspend command and anaddress corresponding to the memory block are received from the memorycontroller while the erase operation on the memory block is beingperformed.

In an embodiment, the erase operation controller 2212 a may restart anerase operation on a memory block when an erase restart command and anaddress corresponding to the memory block are received from the memorycontroller while the erase operation on the memory block is beingsuspended. That the erase operation on the memory block is restarted maymean that an erase voltage is again applied to the memory block from thebeginning.

The erase suspend count manager 2212 b may count a number of times anerase operation on a memory block is suspended until the erase operationon the memory bock is completed (which may be referred to as an erasesuspend count), and manage the erase suspend count corresponding to thememory block. In other words, the erase suspend count manager 2212 b maymanage an erase suspend count with respect to each of a plurality ofmemory blocks. For example, when an erase suspend command and an addressare received from the memory controller, the erase operation controller2212 a may notify the erase suspend count manager 2212 b that the erasesuspend command with respect to the corresponding address has beenreceived. When that notification is received, the erase suspend countmanager 2212 b may increase, by 1, an erase suspend count of a memoryblock to which the corresponding address points. To this end, the erasesuspend count manager 2212 b may have address information for eachmemory block, which is stored therein. In some embodiments, the addressinformation for each memory block may be stored in a separate storagelocated in the memory device, and the erase suspend count manager 2212 bmay refer to the address information for each memory block, which isstored in the separate storage. The erase suspend count may bemaintained until a soft program operation or normal program operation onthe corresponding memory block is performed, and the erase suspend countof the corresponding memory block may be initialized when the softprogram operation or normal program operation on the correspondingmemory block is performed.

The program parameter value determiner 2212 c may determine at least oneparameter value used for a program operation, and provide the determinedparameter value to the program operation controller 2212 e. The programoperation may include at least one of a soft program operation and anormal program operation. Parameters used for the program operation mayinclude at least one of a program start voltage, a number of programloops to be executed, and a program step voltage, but embodiments of thepresent disclosure are not limited thereto.

In an embodiment, when a request is received from the program operationcontroller 2212 e, the program parameter value determiner 2212 c maydetermine at least one parameter value to be used for a programoperation on a memory block. For example, the program operationcontroller 2212 e may request the program parameter value determiner2212 c to provide at least one parameter value to be used for a programoperation on a memory block on which the program operation is to beperformed while providing information (e.g., an index) of thecorresponding memory block to the program parameter value determiner2212 c. In some embodiments, the program operation controller 2212 e mayfurther provide the program parameter value determiner 2212 c withinformation on whether the program operation to be performed on thememory block is a soft program operation or normal program operation.

The program parameter value determiner 2212 c may request the erasesuspend count manager 2212 b to provide an erase suspend countcorresponding to the memory block corresponding to the information(e.g., the index) received from the program operation controller 2212 e.Accordingly, the erase suspend count manager 2212 b may provide theprogram parameter value determiner 2212 c with an erase suspend countcorresponding to the memory block.

The program parameter value determiner 2212 c may determine at least oneparameter value to be used for a program operation on the memory block,based on the erase suspend count corresponding to the memory block. Inan embodiment, the program parameter value determiner 2212 c maydetermine a program start voltage to increase when the erase suspendcount corresponding to the memory block increases. In an embodiment, theprogram parameter value determiner 2212 c may determine a number ofprogram loops to increase when the erase suspend count corresponding tothe memory block increases. In an embodiment, the program parametervalue determiner 2212 c may determine a program step voltage to increasewhen the erase suspend count corresponding to the memory blockincreases. In an embodiment, the program parameter value determiner 2212c may determine a parameter value differently depending on whether theprogram operation to be performed on the memory block is a soft programoperation or normal program operation. For example, the programparameter value determiner 2212 may determine a program start voltagefor the soft program operation to have a lower voltage level than aprogram start voltage for the normal program operation. For example, theprogram parameter value determiner 2212 may determine a number ofprogram loops for the soft program operation to be smaller than a numberof program loops for the normal program operation. For example, theprogram parameter value determiner 2212 may determine a program stepvoltage for the soft program operation to have a lower voltage levelthan a program step voltage for the normal program operation.

In an embodiment, the program parameter value determiner 2212 cdetermines a parameter value used for the program operation by referringto a set program parameter policy. The program parameter policy maydefine different parameter values corresponding to the number of timesan erase operation is suspended.

The program parameter value determiner 2212 c may select a parametervalue corresponding to the erase suspend count corresponding to thememory block on which the program operation is to be performed byreferring to the program parameter policy. The program parameter valuedeterminer 2212 c may determine the selected parameter value as aparameter value for the program operation on the memory block.

In an embodiment, the program parameter policy may include a firstprogram parameter policy corresponding to the soft program operation anda second program parameter policy corresponding to the normal programoperation. When the program operation to be performed on the memoryblock is the soft program operation, the program parameter valuedeterminer 2212 c may determine a parameter value with reference to thefirst program parameter policy. When the program operation to beperformed on the memory block is the normal program operation, theprogram parameter value determiner 2212 c may determine a parametervalue with reference to the second program parameter policy.

The policy storage 2212 d may store the program parameter policy. Forexample, the policy storage 2212 d may store at least one of the firstprogram parameter policy corresponding to the soft program operation andthe second program parameter policy corresponding to the normal programoperation.

The program operation controller 2212 e may control a program operationon a memory block. For example, the program operation controller 2212 emay perform at least one of a soft program operation and a normalprogram operation on the memory block. At least one of the soft programoperation and the normal program operation may be performed using anIncremental Step Pulse Programming (ISPP) scheme.

When an erase operation on a memory block is completed, the programoperation controller 2212 e may perform a soft program operation on thememory block. The program operation controller 2212 e may request theprogram parameter value determiner 2212 c to transmit a parameter valueto be used for the soft program operation on the memory block. Theprogram operation controller 2212 e may receive at least one parametervalue to be used for the soft program operation from the programparameter value determiner 2212 c. The program operation controller 2212e may perform the soft program operation on the memory block, using theat least one parameter value received from the program parameter valuedeterminer 2212 c.

In an embodiment, when an erase operation on a memory block iscompleted, the program operation controller 2212 e may perform a softprogram operation on the memory block through autonomous determination.In an embodiment, when a command for instructing the memory device toperform a soft program operation on a memory block of which an eraseoperation has been completed is received from the memory controller, theprogram operation controller 2212 e may perform the soft programoperation on the memory block.

When a command for a normal program operation, an address, and data arereceived from the memory controller, the program operation controller2212 e may perform the normal program operation on a memory blockcorresponding to the received address.

When a command for instructing the memory device to perform a normalprogram operation is received from the memory controller, the programoperation controller 2212 e may request the program parameter valuedeterminer 2212 c to transmit a parameter value to be used in the normalprogram operation on the corresponding memory block, and receive atleast one parameter value to be used in the normal program operationfrom the program parameter value determiner 2212 c. The programoperation controller 2212 e may perform the normal program operation onthe memory block, using the at least one parameter value received fromthe program parameter value determiner 2212 c.

FIG. 5 is a diagram illustrating an example of managing an erase suspendcount for each memory block.

Here, the memory device includes i (i is a natural number) memory blocksBLK1 to BLKi. Thus, the control logic may manage an erase suspend countfor each of the i memory blocks BLK1 to BLKi. That is, the control logicmay manage how many times erase operation on a memory block is suspendeduntil the erase operation for the memory block is completed. In otherwords, the control logic may manage a number of times an erase suspendcommand on a memory block is received while an erase operation on thememory block is being performed.

In the example of FIG. 5, an erase suspend count of the memory blockBLK1 is 2, an erase suspend count of the memory block BLK2 is 0, anerase suspend count of the memory block BLK3 is 1, and an erase suspendcount of the memory block BLKi is 3.

FIG. 6 is a diagram illustrating an exemplary threshold voltagedistribution of memory cells on which a normal program operation isperformed.

FIG. 6 illustrates, by way of example, a threshold voltage distributionof memory cells in one memory block, which cells operate in a 2-bit MLCmode.

Each of the memory cells operating in the 2-bit MLC mode may have athreshold voltage corresponding to any one of four states. For example,each of the memory cells operating in the 2-bit MLC mode may have athreshold voltage corresponding to an erase state E0, a first programstate P1, a second program state P2, or a third program state P3.

FIG. 6 illustrates, by way of example, a memory block that includes 4000memory cells, which are distributed equally among the four (4) statesidentified above.

FIG. 7 is a diagram illustrating an exemplary erase pulse applied in anerase operation.

FIG. 7 illustrates, as an example, application of an erase pulse for 5ms in an erase operation on a memory block. That is, the erase operationon the memory block may be performed during a time for which the erasepulse is applied.

While FIG. 7 illustrates that one erase pulse is applied in an eraseoperation on a memory block, the present invention is not limited tothat arrangement. In some embodiments, two or more erase pulses may beapplied in an erase operation.

FIG. 8 is a diagram illustrating an exemplary threshold voltagedistribution of memory cells on which an erase operation is performed.

In the embodiment of FIG. 8, one memory block includes 4000 memory cellsoperating in a 2-bit MLC mode.

When an erase operation on a memory block is completed, all memory cellsin the memory block may have a threshold voltage corresponding to theerase state E0. Referring to FIG. 8, it can be seen that memory cellshaving the first program state P1, the second program state P2, and thethird program state P3 have all been changed to the erase state E0.

Some of the memory cells in the erase state E0 may have a thresholdvoltage lower than a set value, e.g., a minimum threshold voltage. Theslashed portion in FIG. 8 shows a threshold voltage distribution of suchmemory cells. These memory cells, i.e. those having the thresholdvoltage lower than the minimum threshold voltage, may be referred to asover-erased or deeply erased memory cells. The over-erased memory cellsmay become a factor that delays a program operation time when a normalprogram operation is performed later. In addition, when the normalprogram operation is performed on over-erased memory cells, theretention performance of the corresponding memory cells may bedeteriorated.

FIG. 9 is a diagram illustrating an exemplary threshold voltagedistribution of memory cells on which a soft program operation isperformed.

The memory device 2200 may perform a soft program operation forincreasing a threshold voltage of over-erased memory cells throughautonomous determination or in response to a request from the memorycontroller. The soft program operation may be performed such that athreshold voltage of all memory cells corresponding to the erase stateE0 is higher than the minimum threshold voltage.

Referring to FIG. 9, it can be seen that the threshold voltagedistribution of the memory cells corresponding to the erase state E0 hasbeen moved right along the threshold voltage axis to a higher thresholdas compared with the case shown in FIG. 8. That is, it can be seen thatall the memory cells having the erase state E0 have a threshold voltagegreater than or equal to the minimum threshold voltage.

FIG. 10 is a diagram illustrating an exemplary process of suspending andrestarting an erase operation.

In the embodiment of FIG. 10, an erase operation is completed when oneerase pulse is applied to a memory block for 5 ms without pause.

First, when an erase command is received, erase pulse 1 may be appliedto the memory block. After such pulse has been applied for 3 ms, anerase suspend command is received. Thus, the erase operation on thememory block may be performed for the first 3 ms. However, the eraseoperation may be suspended for the remaining 2 ms. Since the erase pulse1 is applied to the memory block for 3 ms, a threshold voltage of memorycells in the memory block may be decreased a certain amount.

Subsequently, an erase restart command may be received, and erase pulse2 may be applied to the memory block. The erase pulse 2 is to be appliedto the memory block for 5 ms such that the erase operation on the memoryblock is completed. That is, although the erase operation is suspendedafter the erase pulse 1 is applied for 3 ms, the erase pulse 2 is to beapplied to the memory block for 5 ms.

When the erase operation is suspended and then restarted, the thresholdvoltage of the memory cells may be decreased as compared with asituation in which the erase operation is not suspended. That is, anerase depth of the memory cells may vary depending on a number of timesthe erase operation is suspended.

FIG. 11 is a diagram illustrating an exemplary threshold voltagedistribution of memory cells depending on an erase suspend count.

In FIG. 11, threshold voltage distributions when the erase suspend countis 0, 1 and 2 are illustrated as examples.

Referring to FIG. 11, it can be seen that the threshold voltagedistribution of memory cells moves left along the threshold voltage axisto lower thresholds as the erase suspend count increases. That is, anerase depth of the memory cells increases when the erase suspend countincreases. This may mean that the number of over-erased memory cellsincreases when the erase suspend count increases. Referring to FIG. 11,it can be seen that, when the erase suspend count is 1, the number ofover-eased memory cells is greater as compared with when the erasesuspend count is 0. Similarly, it can be seen that, when the erasesuspend count is 2, the number of over-eased memory cells is greater ascompared with when the erase suspend counter is 1.

Thus, determining different parameter values to be used for a softprogram operation or normal program operation on a memory blockaccording to an erase suspend count corresponding to the memory blockcan help shorten the time for performing the soft program operation orthe normal program operation.

FIG. 12 is a diagram illustrating an exemplary program parameter policyin accordance with an embodiment of the present disclosure.

In FIG. 12, a first program parameter policy for the soft programoperation and a second program parameter policy for the normal programoperation are illustrated as an example. In some embodiments, three ormore program parameter policies may be used, and in other embodimentsonly one program parameter policy may be used. For example, the firstprogram parameter policy may be used for the soft program operation andthe normal program operation.

Referring to FIG. 12, the program parameter policies define parametervalues for each erase suspend count. In FIG. 12, a case where a programstart voltage, a number of program loops, and a program step voltage aredefined as parameters is illustrated as an example, but the presentinvention is not limited to this combination of parameters. For each ofj+1 erase suspend counts, a set of values for program start voltage,number of program loops and program step voltage is defined in eachpolicy.

The first program parameter policy defines that, when the erase suspendcount of a memory block is 0, A0 is used as the program start voltage,B0 is used as the number of program loops, and C0 is used as the programstep voltage. Similarly, the first program parameter policy definesparameter values corresponding to when the erase suspend count of thememory block is j (j is a natural number). The control logic maydetermine at least one parameter value to be used for the soft programoperation with reference to the first program parameter policy.

The second program parameter policy defines that, when the erase suspendcount of a memory block is 0, A0′ is used as the program start voltage,B0′ is used as the number of program loops, and C0′ is used as theprogram step voltage. Similarly, the second program parameter policydefines parameter values corresponding to when the erase suspend countof the memory block is j (j is a natural number). The control logic maydetermine at least one parameter value to be used for the normal programoperation with reference to the second program parameter policy. Theparameters defined in the first program parameter policy may bedifferent from those defined in the second program parameter policy. Forexample, a program start voltage Aj defined in the first programparameter policy may be lower than a program start voltage Aj′ definedin the second program parameter policy. For example, a number of programloops Bj defined in the first program parameter policy may be smallerthan a number of program loops Bj′ defined in the second programparameter policy. For example, a program step voltage Cj defined in thefirst program parameter policy may be lower than a program step voltageCj′ defined in the second program parameter policy.

FIGS. 13 to 16 are diagrams illustrating an exemplary program parameterselected in a program operation using the ISPP scheme.

The program operation using the ISPP scheme, which is described withreference to FIGS. 13 to 16, may be applied to the soft programoperation and the normal program operation.

In FIG. 13, a case where the erase suspend count of a memory block is 0is illustrated as an example. Referring to FIG. 13, applying a programvoltage to the memory block and applying a verify voltage Vf to thememory block may constitute one program loop. In FIG. 13, a case wherethe program loop is performed three times is illustrated as an example.A program voltage used in a first program loop may be referred to as afirst program start voltage Vpgm1. Whenever the program loop isrepeated, the program voltage may be increased by a first step voltageAV1, and a threshold voltage of memory cells may be increased by theincreased program voltage.

In FIG. 14, a program voltage when the erase suspend count of the memoryblock exceeds 0 is illustrated as an example. As described above, theprogram start voltage may increase as the erase suspend count of thememory block increases. Referring to FIG. 14, it can be seen that asecond program start voltage Vpgm2 higher than the first program startvoltage Vpgm1 described with reference to FIG. 13 is used in a firstprogram loop.

In FIG. 15, a program step voltage when the erase suspend count of thememory block exceeds 0 is illustrated as an example. As described above,the program step voltage may increase as the erase suspend count of thememory block increases. Referring to FIG. 15, it can be seen that asecond step voltage AV2 higher than the first step voltage AV1 describedwith reference to FIG. 13 is used.

In FIG. 16, program loops when the erase suspend count of the memoryblock exceeds 0 are illustrated as an example. As described above, anumber of program loops may increase as the erase suspend count of thememory block increases. Referring to FIG. 16, it can be seen that thenumber of program loops performed is greater than that performed in FIG.13.

FIG. 17 is a flowchart illustrating an operating method of the memorydevice in accordance with an embodiment of the present disclosure.

In some embodiments, at least one of steps shown in FIG. 17 may beomitted, and the order of the steps may be changed.

In step 1701, the memory device may receive an erase command and anaddress. The address may correspond to one or more memory blocks.

In step 1703, the memory device may perform an erase operation on amemory block corresponding to the address received in the step 1701.

In step 1705, the memory device may check whether the erase operation onthe memory block is completed. When the erase operation on the memoryblock is completed (Y at step 1705), step 1721 may be performed. Whenthe erase operation on the memory block is not completed (N at step1705), step 1711 may be performed.

In the step 1711, the memory device may check whether an erase suspendcommand and an address are received. If so, (Y at step 1711), step 1713may be performed. If not, (N at step 1711), the step 1703 may beperformed.

In the step 1713, the memory device may suspend the current eraseoperation on the memory block corresponding to the address received. Thememory device may increase, by 1, an erase suspend count correspondingto the memory block on which the erase operation is suspended.

In step 1715, the memory device may check whether an erase restartcommand and an address are received. When the erase restart command andthe address are received (Y at step 1715), the process returns to step1703 where an erase operation on the memory block corresponding to thereceived address may be restarted. When the erase restart command andthe address are not received (N at step 1715), a state in which theerase operation on the memory block is suspended may be maintained untilthe erase restart command and the address are received.

In the step 1721, the memory device may manage or store a number oftimes the erase operation is suspended during the erase operation,corresponding to the memory block.

FIG. 18 is a flowchart illustrating an operating method of the memorydevice in accordance with an embodiment of the present disclosure.

In some embodiments, at least one of steps shown in FIG. 18 may beomitted, and the order of the steps may be changed.

In step 1801, a soft program operation or normal program operation on amemory block may be requested. When a command instructing the memorydevice to perform the soft program operation on the memory block isreceived, the memory device may determine that the soft programoperation on the memory block is requested. In another example, when anerase operation on the memory block is completed, the memory device maydetermine that the soft program operation on the memory block isrequested. As for the normal program operation, when a program command,an address, and data are received from the memory controller, the memorydevice may determine that the normal program operation on the memoryblock is requested.

In step 1803, the memory device may check an erase suspend countcorresponding to the memory block for which the soft program operationor normal program operation is requested.

In step 1805, the memory device may determine a program parameter valueto be applied to the memory block for which the soft program operationor normal program operation is requested. In an embodiment, the programparameter value may be determined based on an erase suspend countcorresponding to the memory block and a set program parameter policy.

In step 1807, the memory device may perform the soft program operationor normal program operation on the memory block, using the determinedprogram parameter value.

FIG. 19 is a diagram illustrating an exemplary memory block.

A memory cell array may include a plurality of memory blocks. Arepresentative memory block BLKi among the plurality of memory blocks isillustrated in FIG. 19.

In the memory block BLKi, a plurality of word lines arranged in parallelto one another may be connected between a first select line and a secondselect line. The first select line may be a source select line SSL, andthe second select line may be a drain select line DSL. Specifically, thememory block BLKi may include a plurality of strings ST connectedbetween bit lines BL1 to BLm and a source line SL. The bit lines BL1 toBLm may be connected to the strings ST, respectively, and the sourceline SL may be commonly connected to the strings ST. The strings ST maybe configured identically to one another, and therefore, a string STconnected to a first bit line BL1 will be described in detail as anexample.

The string ST may include a source select transistor SST, a plurality ofmemory cells F1 to F16, and a drain select transistor DST, which areconnected in series to each other between the source line SL and thefirst bit line BL1. At least one source select transistor SST and atleast one drain select transistor DST may be included in one string ST,and more than the 16 memory cells F1 to F16 shown in the drawing may beincluded in one string ST.

A source of the source select transistor SST may be connected to thesource line SL, and a drain of the drain select transistor DST may beconnected to the first bit line BL1. The memory cells F1 to F16 may beconnected in series between the source select transistor SST and thedrain select transistor DST. Gates of source select transistors SSTincluded in different strings ST may be connected to the source selectline SSL, gates of drain select transistors DST included in differentstrings ST may be connected to the drain select line DSL, gates of thememory cells F1 to F16 included in different strings ST may be connectedto a plurality of word lines WL1 to WL16. A group of memory cellsconnected to the same word line among the memory cells included indifferent strings ST may be a physical page PPG. Therefore, physicalpages PPG of which number corresponds to that of the word lines WL1 toWL16 may be included in the memory block BLKi.

FIG. 20 is a diagram illustrating an embodiment a three-dimensionallyconfigured memory block.

The memory cell array may include a plurality of memory blocks BLK1 toBLKi. Since each of the blocks BLK1 to BLKi may be configured the same,a first memory block BLK1 is described as an example. The first memoryblock BLK1 may include a plurality of strings ST11 to ST1 m and ST21 toST2 m. In an embodiment, each of the plurality of strings ST11 to ST1 mand ST21 to ST2 m may be formed in a ‘U’ shape. In the first memoryblock BLK1, m strings may be arranged in a row direction (X direction).Although FIG. 20 illustrates that two strings are arranged in a columndirection (Y direction), this is for clarity; three or more strings maybe arranged in the column direction (Y direction).

Each of the plurality of strings ST11 to ST1 m and ST21 to ST2 m mayinclude at least one source select transistor SST, first to nth memorycells MC1 to MCn, a pipe transistor PT, and at least one drain selecttransistor DST.

The source and drain select transistors SST and DST and the memory cellsMC1 to MCn may have structures similar to one another. For example, eachof the source and drain select transistors SST and DST and the memorycells MC1 to MCn may include a channel layer, a tunnel insulating layer,a charge trapping layer, and a blocking insulating layer. For example, apillar for providing the channel layer may be provided in each string.For example, a pillar for providing at least one of the channel layer,the tunnel insulating layer, the charge trapping layer, and the blockinginsulating layer may be provided in each string.

The source select transistor SST of each string may be connected betweena source line SL and memory cells MC1 to MCp.

In an embodiment, source select transistors of strings arranged in thesame row may be connected to a source select line extending in the rowdirection, and source select transistors of strings arranged indifferent rows may be connected to different source select lines. InFIG. 20, source select transistors of strings ST11 to ST1 m of a firstrow may be connected to a first source select line SSL1. Source selecttransistors of strings ST21 to ST2 m of a second row may be connected toa second source select line SSL2.

In another embodiment, the source select transistors of the strings ST11to ST1 m and ST21 to ST2 m may be commonly connected to one sourceselect line.

First to nth memory cells MC1 to MCn of each string may be connectedbetween the source select transistor SST and the drain select transistorDST.

The first to nth memory cells MC1 to MCn may be divided into first topth memory cells MC1 to MCp and (p+1)th to nth memory cells MCp+1 toMCn. The first to pth memory cells MC1 to MCp may be sequentiallyarranged in a vertical direction (Z direction), and be connected inseries to each other between the source select transistor SST and thepipe transistor PT. The (p+1)th to nth memory cells MCp+1 to MCn may besequentially arranged in the vertical direction (Z direction), and beconnected in series to each other between the pipe transistor PT and thedrain select transistor DST. The first to pth memory cells MC1 to MCpand the (p+1)th to nth memory cells MCp+1 to MCn may be connected toeach other through the pipe transistor PT. Gates of the first to nthmemory cells MC1 to MCn of each string may be connected to first to nthword lines WL1 to WLn, respectively.

In an embodiment, at least one of the first to nth memory cells MC1 toMCn may be used as a dummy memory cell. When a dummy memory cell isprovided, the voltage or current of a corresponding string can be stablycontrolled. A gate of the pipe transistor PT of each string may beconnected to a pipe line PL.

The drain select transistor DST of each string may be connected to a bitline and the memory cells MCp+1 to MCn. Strings arranged in the rowdirection may be connected to a drain select line extending in the rowdirection. Drain select transistors of the strings ST11 to ST1 m, of thefirst row may be connected to a first drain select line DSL1. Drainselect transistors of the strings ST21 to ST2 m of the second row may beconnected to a second drain select line DSL2.

Strings arranged in the column direction may be connected to bit linesextending in the column direction. In FIG. 20, strings ST11 and ST21 ofa first column may be connected to a first bit line BL1. Strings ST1 mand ST2 m of an mth column may be connected to an mth bit line BLm.

Memory cells connected to the same word line among the strings arrangedin the row direction may constitute one page. For example, memory cellsconnected to the first word line WL1 among the strings ST11 to ST1 m ofthe first row may constitute one page. Memory cells connected to thefirst word line WL1 among the strings ST21 to ST2 m of the second rowmay constitute another page. When any one of the drain select lines DSL1and DSL2 is selected, strings arranged in one row direction may beselected. When any one of the word lines WL1 to WLn is selected, onepage among the selected strings may be selected.

FIG. 21 is a diagram illustrating another embodiment thethree-dimensionally configured memory block.

The memory cell array may include a plurality of memory blocks BLK1 toBLKi, which may be configured the same. Thus, a first memory block BLK1is described as an example. The first memory block BLK1 may include aplurality of strings ST11′ to ST1 m′ and ST21′ to ST2 m′. Each of theplurality of strings ST11′ to ST1 m′ and ST21′ to ST2 m′ may extendalong a vertical direction (Z direction). In the first memory blockBLK1, m′ strings may be arranged in a row direction (X direction).Although FIG. 21 illustrates that two strings are arranged in a columndirection (Y direction), this is for clarity; three or more strings maybe arranged in the column direction (Y direction).

Each of the plurality of strings ST11′ to ST1 m′ and ST21′ to ST2 m′ mayinclude at least one source select transistor SST, first to nth memorycells MC1 to MCn, and at least one drain select transistor DST.

The source select transistor SST of each string may be connected betweena source line SL and the memory cells MC1 to MCn. Source selecttransistors of strings arranged in the same row may be connected to thesame source select line. Source select transistors of strings ST11′ toST1 m′ arranged on a first row may be connected to a first source selectline SSL1. Source select transistors of strings ST21′ to ST2 m′ arrangedon a second row may be connected to a second source select line SSL2. Inanother embodiment, the source select transistors of the strings ST11′to ST1 m′ and ST21′ to ST2 m′ may be commonly connected to one sourceselect line.

The first to nth memory cells MC1 to MCn of each string may be connectedin series to each other between the source select transistor SST and thedrain select transistor DST. Gates of the first to nth memory cells MC1to MCn may be connected to first to nth word lines WL1 to WLn,respectively.

In an embodiment, at least one of the first to nth memory cells MC1 toMCn may be used as a dummy memory cell. When a dummy memory cell isprovided, the voltage or current of a corresponding string can be stablycontrolled. Accordingly, the reliability of data stored in the firstmemory block BLK1 can be improved.

The drain select transistor DST of each string may be connected betweena bit line and the memory cells MC1 to MCn. Drain select transistors DSTof strings arranged in the row direction may be connected to a drainselect line extending in the row direction. The drain select transistorsDST of the strings ST11′ to ST1 m′ of the first row may be connected toa first drain select line DSL1. The drain select transistors DST of thestrings ST21′ to ST2 m′ of the second row may be connected to a seconddrain select line DSL2.

That is, the first memory block BLK1 of FIG. 21 may have a circuitidentical to that of the first memory block BLK1 of FIG. 20, except thatthe pipe transistor PT is excluded from each string.

FIG. 22 is a diagram illustrating another example of the memory systemincluding the memory controller shown in FIGS. 1 to 3.

Referring to FIG. 22, the memory system 30000 may be implemented as acellular phone, a smart phone, a tablet PC, a personal digital assistant(PDA), or a wireless communication device. The memory system 30000 mayinclude a memory device 2200 and a memory controller 2100 capable ofcontrolling an operation of the memory device 2200.

The memory controller 2100 may control a data access operation of thememory device 2200, e.g., a program operation, an erase operation, aread operation, or the like under the control of a processor 3100.

Data programmed in the memory device 2200 may be output through adisplay 3200 under the control of the memory controller 2100.

A radio transceiver 3300 may transmit/receive radio signals through anantenna ANT. For example, the radio transceiver 3300 may convert a radiosignal received through the antenna ANT into a signal that can beprocessed by the processor 3100. Therefore, the processor 3100 mayprocess a signal output from the radio transceiver 3300 and transmit theprocessed signal to the memory controller 2100 or the display 3200. Thememory controller 2100 may transmit the signal processed by theprocessor 3100 to the memory device 2200. Also, the radio transceiver3300 may convert a signal output from the processor 3100 into a radiosignal, and output the radio signal to an external device through theantenna ANT. An input device 3400 is a device capable of inputting acontrol signal for controlling an operation of the processor 3100 ordata to be processed by the processor 3100, and may be implemented as apointing device such as a touch pad or a computer mount, a keypad, or akeyboard. The processor 3100 may control an operation of the display3200 such that data output from the memory controller 2100, data outputfrom the radio transceiver 3300, or data output from the input device3400 can be output through the display 3200.

In some embodiments, the memory controller 2100 capable of controllingan operation of the memory device 2200 may be implemented as a part ofthe processor 3100, or be implemented as a chip separate from theprocessor 3100.

FIG. 23 is a diagram illustrating another example of the memory systemincluding the memory controller shown in FIGS. 1 to 3.

Referring to FIG. 23, the memory system 40000 may be implemented as apersonal computer (PC), a tablet PC, a net-book, an e-reader, a personaldigital assistant (PDA), a portable multimedia player (PMP), an MP3player, or an MP4 player.

The memory system 40000 may include a memory device 2200 and a memorycontroller 2100 capable of controlling a data processing operation ofthe memory device 2200.

A processor 4100 may output data stored in the memory device 2200through a display 4300 according to data input through an input device4200. For example, the input device 4200 may be implemented as apointing device such as a touch pad or a computer mouse, a keypad, or akeyboard.

The processor 4100 may control overall operations of the memory system40000, and control an operation of the memory controller 2100. In someembodiments, the memory controller 2100 capable of controlling anoperation of the memory device 2200 may be implemented as a part of theprocessor 4100, or be implemented as a chip separate from the processor4100.

FIG. 24 is a diagram illustrating another example of the memory systemincluding the memory controller shown in FIGS. 1 to 3.

Referring to FIG. 24, the memory system 50000 may be implemented as animage processing device, e.g., a digital camera, a mobile terminalhaving a digital camera attached thereto, a smart phone having a digitalcamera attached thereto, or a tablet PC having a digital camera attachedthereto.

The memory system 50000 may include a memory device 2200 and a memorycontroller 2100 capable of controlling a data processing operation ofthe memory device 2200, e.g., a program operation, an erase operation,or a read operation.

An image sensor 5200 of the memory system 50000 may convert an opticalimage into digital signals, and the converted digital signals may betransmitted to a processor 5100 or the memory controller 2100. Under thecontrol of the processor 5100, the converted digital signals may beoutput through a display 5300, or be stored in the memory device 2200through the memory controller 2100. In addition, data stored in thememory device 2200 may be output through the display 5300 under thecontrol of the processor 5100 or the memory controller 2100.

In some embodiments, the memory controller 2100 capable of controllingan operation of the memory device 2200 may be implemented as a part ofthe processor 5100, or be implemented as a chip separate from theprocessor 5100.

FIG. 25 is a diagram illustrating another example of the memory systemincluding the memory controller shown in FIGS. 1 to 3.

Referring to FIG. 25, the memory system 70000 may be implemented as amemory card or a smart card. The memory system 70000 may include amemory device 2200, a memory controller 2100, and a card interface 7100.

The memory controller 2100 may control data exchange between the memorydevice 2200 and the card interface 7100. In some embodiments, the cardinterface 7100 may be a Secure Digital (SD) card interface or aMulti-Media Card (MMC) interface, but the present disclosure is notlimited thereto.

The card interface 7100 may interface data exchange between a host 60000and the memory controller 2100 according to a protocol of the host60000. In some embodiments, the card interface 7100 may support aUniversal Serial Bus (USB) protocol and an Inter-Chip (IC)-USB protocol.The card interface 7100 may mean hardware capable of supporting aprotocol used by the host 60000, software embedded in the hardware, or asignal transmission scheme.

When the memory system 70000 is connected to a host interface 6200 ofthe host 60000 such as a PC, a tablet PC, a digital camera, a digitalaudio player, a cellular phone, console video game hardware, or adigital set-top box, the host interface 6200 may perform datacommunication with the memory device 2200 through the card interface7100 and the memory controller 2100 under the control of amicroprocessor (oP) 6100.

In accordance with embodiments of the present disclosure, a thresholdvoltage of over-erased memory cells can be increased in advance, andhence the retention performance of memory cells can be improved when anormal program operation is performed on the memory cells.

In accordance with embodiments of the present disclosure, a thresholdvoltage of over-erased memory cells can be increased in advance, andhence the time required to perform a normal program operation can bereduced.

Various embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present disclosure asset forth in the following claims.

What is claimed is:
 1. A memory device comprising: an operationcontroller configured to perform an erase operation on a memory blockand to perform a program operation on the memory block based on aparameter value; an erase suspend count manager configured to store anerase suspend count representing a number of times the erase operationis suspended until the erase operation on the memory block is completed;and a program parameter value determiner configured to store theparameter value to be used for the program operation on the memoryblock, based on the erase suspend count, wherein the parameter valueincludes a program start voltage.
 2. The memory device of claim 1,further comprising a program operation controller configured to performthe program operation on the memory block, using the stored parametervalue.
 3. The memory device of claim 1, wherein the program operation isa soft program operation or a normal program operation.
 4. The memorydevice of claim 1, wherein the parameter value further includes a numberof program loops and a program step voltage.
 5. The memory device ofclaim 4, wherein the program parameter value determiner determines theprogram start voltage to have a higher voltage level as the erasesuspend count increases.
 6. The memory device of claim 4, wherein theprogram parameter value determiner determines the number of programloops to be greater as the erase suspend count increases.
 7. The memorydevice of claim 4, wherein the program parameter value determinerdetermines the program step voltage to have a higher voltage level asthe erase suspend count increases.
 8. The memory device of claim 1,wherein the program parameter value determiner determines the parametervalue corresponding to the erase suspend count according to a programparameter policy defining parameter values with respect to a number oftimes an erase operation is suspended.
 9. The memory device of claim 8,wherein the program parameter policy includes at least one of a firstprogram parameter policy corresponding to a soft program operation and asecond program parameter policy corresponding to a normal programoperation.
 10. The memory device of claim 8, further comprising a policystorage configured to store the program parameter policy.
 11. A methodfor operating a memory device, the method comprising: performing anerase operation on a memory block; suspending the erase operation on thememory block in response to an erase suspend command during the eraseoperation; resuming the erase operation on the memory block in responseto an erase resume command on the memory block while the erase operationon the memory block is suspended; generating a counted numberrepresenting a number of times the erase operation is suspended untilthe erase operation on the memory block is completed; and performing aprogram operation according to a parameter value determined based on thecounted number, wherein the parameter value includes a program startvoltage.
 12. The method of claim 11, wherein the program operation is asoft program operation or normal program operation.
 13. The method ofclaim 11, wherein the parameter value further includes a number ofprogram loops or a program step voltage.
 14. The method of claim 13,wherein the program start voltage has a higher voltage level as thecounted number increases.
 15. The method of claim 13, wherein the numberof program loops is greater as the counted number increases.
 16. Themethod of claim 13, wherein the program step voltage has a highervoltage level as the counted number increases.
 17. The method of claim11, wherein the parameter value corresponding to the counted number isdetermined in accordance with a program parameter policy definingparameter values with respect to a number of times the erase operationis suspended.
 18. A memory device comprising: a memory block configuredto store data; a peripheral circuit configured to perform erase andprogram operations on the memory block; an erase operation controllerconfigured to control the peripheral circuit to perform the eraseoperation; and a program operation controller configured to control theperipheral circuit to perform the program operation with a parametervalue depending on a number of times the erase operation is suspendeduntil completion thereof, wherein the parameter value includes a programstart voltage.